I'd wager the ammo is fine, that being said I'd do exactly what you said. Replace it with new stuff and shoot it next range visit. We'll be waiting to hear the results.
While at the PD the guys would open boxes of ammo and dump them in a 5 gallon bucket at the range so they were'nt always opening boxes which can be a chore. Just take the bucket with any left over back to the station. Often times it was raining and the bucket would get several inches of water in the bottom. Of course no one but myself would ever bother to empty the water and sometimes that was days after the range session. It was all training ammo but I never heard of any issues of it not firing.
Again if it had been duty ammunition, I would have taken it out of service. (usually brought home for myself) Not worth the risk of a failure.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."